Alfa Laval - Q&A

Q&As about Revos concentration system

Q: How can you guarantee the water quality whilst reconstituting the beer concentrate in a pub? 

A: Revos draft dispense systems require the installation of a 5-micron carbon filter on the feed water line. The filter removes odours and particulates. For many local water supplies, this level of treatment is sufficient. However, if the water hardness or total dissolved solids in the main water supply is high, the installation of an under-the-counter ion exchange unit and/or reverse osmosis water purification unit to feed the draft dispense system is recommended. 


Q: What are the ATEX considerations with beer at 22%+ ABV? 

AATEX requirements (relevant for European installations) are analyzed on a case-by-case basis. Given liquids are fully enclosed in the Revos concentration system, ATEX-rated components are generally not required, provided the concentrates are 24% ABV or less. 


Q: Is it possible to convert the dispense system to 50 Hz? 

A: There is no need to convert the Revos draft dispense system. It is available in both 50 Hz and 60 Hz frequencies. 


Q: How do you measure alcohol concentration in the Revos process? 

A: This is accomplished by measuring the inline density and refractive index and combining these measurements in a proprietary model to calculate the inline alcohol concentration. 


Q: What is the running cycle between Cleaning-in-Place (CIP) for the concentration module? 

A: The concentration module undergoes caustic cleaning at 11.5 pH on a weekly or biweekly basis. This process takes about four hours. Short 30-minute warm deaerated water flushes are also used on a daily or every-other-day basis for membrane regeneration. 


Q: What is the typical timeframe for membrane replacement? 

A:  The recommended interval for membrane replacement is 9 to 12 months, depending primarily on the frequency of CIP. 


Q: Can you provide a complete overview of the savings achieved? Is there a real business case that you can share? 

A: We do not have a business case that we can share publicly at present. A representative all-in number for concentration with Revos is about €1-2 per hl (at sales gravity), with larger installations achieving the lower end of this cost range. Savings are proportional to transport costs. For example, if transport costs are €10/hl for bulk transport, Revos may cut that down by €6.6/hl. For draft dispense applications, savings are often larger. For instance, transport costs may be €20/hl without a concentrate-based approach; a concentrate-based approach may reduce those costs by €16/hl or 80%. The percentage transport savings are typically larger for draft dispense applications because bulk transport is often already done at high gravity. 


Q: As shown on the dearomatization slide, how is it possible for aroma removal to be more than 100%? 

A: Removal of more than 100% of the aroma is not possible. In the presentation, we allowed for a 10% margin of error on the removal rate measurements. 


Q: Is it possible to create instantaneously more beer brands from the same keg (mother beer) by playing with different blending ratios? 

A: Yes, this is possible but may require some software upgrades to the draft dispense technology, depending on the complexity of what is required. 


Q: Is concentrated product filled into kegs or bag-in-boxes (BIBs) using Alfa Laval Astepo as seen on the slide during the webinar? 

A: Revos draft dispense system can handle kegs or BIBs. From 2023, we are considering offering an Alfa Laval BIB filling solution. For 2021 and 2020, the focus will be on kegs as brewers are already equipped with kegs and keg-filling machines. 


Q: What is the maximum concentration that can be achieved? Is it possible to go up to 70% for other beverages by adding an additional membrane? 

A: The maximum concentration is 24%. In the future, Alfa Laval may develop membranes capable of reaching higher concentrations. 


Q: So Revos technology can also be used for applications like dealc or hard seltzer? 

A: Correct, although Alfa Laval only sells the dealc and hard seltzer applications as an add-on to the standard concentration technology. 


Q: Is there a minimum size for a brewery/hard seltzer manufacturing facility? 

A: Our smallest Revos unit (Revos pilot) has a throughput of about 1 hl/h. 


Q: Regarding the Revos draft system: Is ultraviolet (UV) treatment necessary on the water line since the water source is food grade and the blended beer is to be consumed immediately after blending? 

A: UV is not essential, but shelf-life testing shows that it can delay microbial growth downstream of the blending of water and concentrate. Note that the UV light is included as part of the Revos draft dispense technology. 


Q: What kind of water is required for reconstitution? Is there a loss of brewing salts? 

A: Revos removes water in pure form, so the ideal water for reconstitution is water with a low value of total dissolved solids, which is what brewers use for debrewing. Brewing salts present after fermentation are retained in the concentrate by Revos, so there is no loss there. 


Q: How many people are required to operate the Revos concentration systems? 

A: The Revos concentration systems are fully automated. One person is required to replace the membranes after 9 to 12 months. 


Q: What utilities are required for installation of a draft dispense system? 

A: A water supply with a 5-micron carbon filter, electricity and gas. 


Q: Can multiple products be served from the same draft dispense system? 

A: Yes. Revos draft cellar can serve up to four products. Revos draft mobile can serve up to two products.